package com.sadna.widgets.application;

import java.util.ArrayList;

import android.database.*;

public class ExtMatrixCursor extends AbstractCursor {
	
    private final String[] columnNames;
    private Object[] data;
    private int rowCount = 0;
    private final int columnCount;

    /**
     * Constructs a new cursor with the given initial capacity.
     *
     * @param columnNames names of the columns, the ordering of which
     *  determines column ordering elsewhere in this cursor
     * @param initialCapacity in rows
     */
    public ExtMatrixCursor(String[] columnNames, int initialCapacity) {
        this.columnNames = columnNames;
        this.columnCount = columnNames.length;

        if (initialCapacity < 1) {
            initialCapacity = 1;
        }

        this.data = new Object[columnCount * initialCapacity];
    }

    /**
     * Constructs a new cursor.
     *
     * @param columnNames names of the columns, the ordering of which
     *  determines column ordering elsewhere in this cursor
     */
    public ExtMatrixCursor(String[] columnNames) {
        this(columnNames, 16);
    }

    /**
     * Gets value at the given column for the current row.
     */
    private Object get(int column) {
        if (column < 0 || column >= columnCount) {
            throw new CursorIndexOutOfBoundsException("Requested column: "
                    + column + ", # of columns: " +  columnCount);
        }
        if (mPos < 0) {
            throw new CursorIndexOutOfBoundsException("Before first row.");
        }
        if (mPos >= rowCount) {
            throw new CursorIndexOutOfBoundsException("After last row.");
        }
        return data[mPos * columnCount + column];
    }

    /**
     * Adds a new row to the end and returns a builder for that row. Not safe
     * for concurrent use.
     *
     * @return builder which can be used to set the column values for the new
     *  row
     */
    public RowBuilder newRow() {
        rowCount++;
        int endIndex = rowCount * columnCount;
        ensureCapacity(endIndex);
        int start = endIndex - columnCount;
        return new RowBuilder(start, endIndex);
    }

    /**
     * Adds a new row to the end with the given column values. Not safe
     * for concurrent use.
     *
     * @throws IllegalArgumentException if {@code columnValues.length !=
     *  columnNames.length}
     * @param columnValues in the same order as the the column names specified
     *  at cursor construction time
     */
    public void addRow(Object[] columnValues) {
        if (columnValues.length != columnCount) {
            throw new IllegalArgumentException("columnNames.length = "
                    + columnCount + ", columnValues.length = "
                    + columnValues.length);
        }

        int start = rowCount++ * columnCount;
        ensureCapacity(start + columnCount);
        System.arraycopy(columnValues, 0, data, start, columnCount);
    }

    /**
     * Adds a new row to the end with the given column values. Not safe
     * for concurrent use.
     *
     * @throws IllegalArgumentException if {@code columnValues.size() !=
     *  columnNames.length}
     * @param columnValues in the same order as the the column names specified
     *  at cursor construction time
     */
    public void addRow(Iterable<?> columnValues) {
        int start = rowCount * columnCount;
        int end = start + columnCount;
        ensureCapacity(end);

        if (columnValues instanceof ArrayList<?>) {
            addRow((ArrayList<?>) columnValues, start);
            return;
        }

        int current = start;
        Object[] localData = data;
        for (Object columnValue : columnValues) {
            if (current == end) {
                // TODO: null out row?
                throw new IllegalArgumentException(
                        "columnValues.size() > columnNames.length");
            }
            localData[current++] = columnValue;
        }

        if (current != end) {
            // TODO: null out row?
            throw new IllegalArgumentException(
                    "columnValues.size() < columnNames.length");
        }

        // Increase row count here in case we encounter an exception.
        rowCount++;
    }

    /** Optimization for {@link ArrayList}. */
    private void addRow(ArrayList<?> columnValues, int start) {
        int size = columnValues.size();
        if (size != columnCount) {
            throw new IllegalArgumentException("columnNames.length = "
                    + columnCount + ", columnValues.size() = " + size);
        }

        rowCount++;
        Object[] localData = data;
        for (int i = 0; i < size; i++) {
            localData[start + i] = columnValues.get(i);
        }
    }

    /** Ensures that this cursor has enough capacity. */
    private void ensureCapacity(int size) {
        if (size > data.length) {
            Object[] oldData = this.data;
            int newSize = data.length * 2;
            if (newSize < size) {
                newSize = size;
            }
            this.data = new Object[newSize];
            System.arraycopy(oldData, 0, this.data, 0, oldData.length);
        }
    }
    
    @Override
    public void close() {
    	super.close();
    	this.data = null;
    }

    /**
     * Builds a row, starting from the left-most column and adding one column
     * value at a time. Follows the same ordering as the column names specified
     * at cursor construction time.
     */
    public class RowBuilder {

        private int index;
        private final int endIndex;

        RowBuilder(int index, int endIndex) {
            this.index = index;
            this.endIndex = endIndex;
        }

        /**
         * Sets the next column value in this row.
         *
         * @throws CursorIndexOutOfBoundsException if you try to add too many
         *  values
         * @return this builder to support chaining
         */
        public RowBuilder add(Object columnValue) {
            if (index == endIndex) {
                throw new CursorIndexOutOfBoundsException(
                        "No more columns left.");
            }

            data[index++] = columnValue;
            return this;
        }
    }

    // AbstractCursor implementation.

    public int getCount() {
        return rowCount;
    }

    public String[] getColumnNames() {
        return columnNames;
    }

    public String getString(int column) {
        return String.valueOf(get(column));
    }

    public short getShort(int column) {
        Object value = get(column);
        return (value instanceof String)
                ? Short.valueOf((String) value)
                : ((Number) value).shortValue();
    }

    public int getInt(int column) {
        Object value = get(column);
        return (value instanceof String)
                ? Integer.valueOf((String) value)
                : ((Number) value).intValue();
    }

    public long getLong(int column) {
        Object value = get(column);
        return (value instanceof String)
                ? Long.valueOf((String) value)
                : ((Number) value).longValue();
    }

    public float getFloat(int column) {
        Object value = get(column);
        return (value instanceof String)
                ? Float.valueOf((String) value)
                : ((Number) value).floatValue();
    }

    public double getDouble(int column) {
        Object value = get(column);
        return (value instanceof String)
                ? Double.valueOf((String) value)
                : ((Number) value).doubleValue();
    }

    public boolean isNull(int column) {
        return get(column) == null;
    }
    
    @Override
    public byte[] getBlob(int column) {
    	Object value = get(column);
    	return (value instanceof byte[])
    			? (byte[])value
    			: new byte[0];
    }
    
    @Override
    public void fillWindow(int position, CursorWindow window) {
    	if (position < 0 || position > getCount()) {
            return;
        }
        window.acquireReference();
        try {
            int oldpos = mPos;
            mPos = position - 1;
            window.clear();
            window.setStartPosition(position);
            int columnNum = getColumnCount();
            window.setNumColumns(columnNum);
            while (moveToNext() && window.allocRow()) {            
                for (int i = 0; i < columnNum; i++) {
                	Object value = get(i);
                	
                	if (value == null) {
                		if (!window.putNull(mPos, i)) {
                            window.freeLastRow();
                            break;
                        }
                	}                	
                	else if (value instanceof byte[])
                	{                		
                		byte[] val = (byte[])value;
                		window.putBlob(val, mPos, i);
                	}
                	else
                	{
                		String field = getString(i);
                		if (field != null) {
                			if (!window.putString(field, mPos, i)) {
                				window.freeLastRow();
                				break;
                			}
                		}
                    } 
                }
            }
            
            mPos = oldpos;
        } catch (IllegalStateException e){
            // simply ignore it
        } finally {
            window.releaseReference();
        }
    }
    
}